dbconnect.java

源代码

/*  Filename:DBConnect.java */

package staff.database; 

import java.sql.*;

public class DBConnect {
	private String dbUrl;
    private String password;
    private String username;
    private String jdbcClassName;
	private Connection conn = null;
	private Statement stmt = null;


	public DBConnect() throws Exception
    {
		dbUrl = "jdbc:postgresql:postgres";
		jdbcClassName = "org.postgresql.Driver";
		username = "postgres";
		password = "010551";
		connect();
    }

    public DBConnect( String inUrl, String inJdbcClassName, String inUserName, String inPassWord )
    		throws Exception
    {
		dbUrl = inUrl;
		jdbcClassName = inJdbcClassName;
		username = inUserName;
		password = inPassWord;
		connect();
    }
	private boolean connect()throws Exception 
    {
		boolean opened = false;
		Driver driver = (Driver) Class.forName(jdbcClassName).newInstance();
		DriverManager.registerDriver(driver);
		conn = DriverManager.getConnection(dbUrl, username, password);
		stmt = conn.createStatement ();
		opened = true;
	return opened;
    }

    public Connection getDBConnection()
    {
    	return conn;
    }

	public ResultSet executeQuery(String sql) throws SQLException
	{
		if (stmt != null) 
		{
			return stmt.executeQuery(sql);
		} 
		else
			return null;
	}

	public void executeUpdate(String sql) throws SQLException 
	{
		if (stmt != null)
			stmt.executeUpdate(sql);
	}


	public void close() throws Exception
	{
		if (stmt != null) 
		{
			stmt.close();
			stmt = null;
		}		
		if (conn != null)
			conn.close();
    }
}